摘要 |
A method and apparatus for embedding in a surface area of a metal part a plurality of particles of a material having a melting point higher than, and mechanical properties different from, the metal of the part. The metal part is contacted with a pair of contacts, one at each end of the area, and electric current having a frequency of at least 3000 Hz is supplied to the contacts through a proximity conductor or conductors which overlies or overlie the area and which are spaced from the area by not more than five times the conductor width. The current is maintained until the metal of the area reaches a temperature at least equal to the melting temperature thereof and the particles are inserted into the molten metal which is then cooled. If the temperature of the molten metal exceeds the melting temperature of the particles, the molten metal is cooled before the particles completely melt. |